The present invention relates to a battery charging apparatus and, more particularly, to a battery charging apparatus for a motor vehicle.
A battery charging apparatus for a motor vehicle is known comprising a generator having rectifier means, two terminals for at least one battery to be charged, a terminal for at least one consuming device, main voltage regulator means for control of the generator output voltage, means for fault detection, means for fault indication via a charge control lamp and means for protection of the battery charging apparatus from overvoltages.
A battery charging system, in which the occurrence of a single possible fault is indicated or signalled and which can switch to an emergency operation condition in case the fault is detected, for example to an emergency regulation, is already known. For example a battery charging system is described in German Published Patent Application 38 44 442 and/or the related U.S. Pat. No. 5,166,594, in which the battery to be charged is supplied by an alternator, in which a semiconductor-voltage regulator is used to keep the generator output voltage constant.
The operator of the battery charging system is warned promptly by a charge control device, when a fault occurs inside the battery charging system. Simultaneously emergency regulation occurs by means of a separate auxiliary voltage regulator.
The known battery charging system is used in connection with a generator and an associated rectifier bridge, which invariably includes diodes. This fault detection and/or emergency regulation in contrast cannot be used with a rectifier bridge having at least three Zener diodes.